A new device will charge up your cellphones and other gadgets by harnessing the heat of a campfire. The big problem? It's only sold in Japan.

The Hatsuden-Nabe cookpot charger turns heat into electricity fit for charging phones, MP3 players or tablets. It's built to be put out on a campfire and uses a special ceramic material that uses temperature differentials to generate electricity.

The device sells in Japan for around $300 and is being marketed to people affected by the March earthquake and tsunami. The company is planning to expand to developing world countries with spotty energy grids.

I am excited about their potential to do a lot of good around the world, but I would also love to have one of these for camping. Solar is hard to deploy when you're on the move and isn't super effective at small sizes. The perfect charger would work during down time — night time.

Shea Gunther ( @sheagunther ) is a podcaster, writer, and entrepreneur living in Portland, Maine. He hosts the popular podcast "Marijuana Today Daily" and was a founder of Renewable Choice Energy, the country's leading provider of wind credits and Green Options. He plays a lot of ultimate frisbee and loves bad jokes.